Solar composite tube, solar composite bed comprising the same, and solar cold and heat supply system comprising solar composite bed

ABSTRACT

A solar composite tube, including a solar vacuum tube having two open ends; a water path; an adsorbent; and an adsorbate. The solar vacuum tube includes an outer metal tube and an inner metal tube which are coaxially disposed inside the solar vacuum tube. The water path is formed between the outer metal tube and the solar vacuum tube; the adsorbent is disposed between the outer metal tube and the inner metal tube and is configured to exchange heat with water in the water path outside the outer metal tube; the inner metal tube includes a plurality of through holes; the adsorbate is disposed in the inner metal tube; and the adsorbate and the adsorbent form an adsorption-desorption working pair. The invention also provides a solar composite bed including a lower header, an upper header, and the solar composite tube.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of International Patent Application No. PCT/CN2015/082787 with an international filing date of Jun. 30, 2015, designating the United States, now pending, and further claims priority benefits to Chinese Patent Application No. 201410419864.7 filed Aug. 22, 2014. The contents of all of the aforementioned applications, including any intervening amendments thereto, are incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates to a solar composite tube, a solar composite bed comprising the solar composite tube, and a solar cold and heat supply system comprising the solar composition bed.

Description of the Related Art

Fossil fuels, including coal, and natural gas, are used as energy sources in many fields, which contributes to global warming.

Although, solar composite tubes may also be used for heat collection, conventional solar composite tubes have low heat supply efficiency, and have almost no heat storage capacity. In addition, solar energy supply fluctuates with the Earth's rotation around the sun and also is adversely affected by bad weather.

SUMMARY OF THE INVENTION

In view of the above-described problems, it is one objective of the invention to provide a solar composite tube, a solar composite bed, and a solar cold and heat supply system comprising the same. The solar cold and heat supply system has dual functions in supplying cold and heat, specifically, is configured to prepare hot water in the daytime and prepare cold water in the night, or to continuously supply cold water and hot water during the whole day.

To achieve the above objective, in accordance with one embodiment of the invention, there is provided a solar composite tube. The solar composite tube comprises a solar vacuum tube having two open ends; a water path; an adsorbent; and an adsorbate. The solar vacuum tube comprises an outer metal tube and an inner metal tube which are coaxially disposed inside the solar vacuum tube. The water path is formed between the outer metal tube and the solar vacuum tube; the adsorbent is disposed between the outer metal tube and the inner metal tube and is configured to exchange heat with water in the water path outside the outer metal tube; the inner metal tube comprises a plurality of through holes; the adsorbate is disposed in the inner metal tube; and the adsorbate and the adsorbent form an adsorption-desorption working pair.

In a class of this embodiment, the through holes on the inner metal tube have diameters of between 1 and 2 mm.

In a class of this embodiment, the adsorption-desorption working pair comprises a gaseous adsorbate and a solid adsorbent.

In a class of this embodiment, the adsorption-desorption working pair is methanol-active carbon or ammonia-active carbon.

To solve the above technical problem, it is one objective of the invention to provide a solar composite bed comprising the solar composite tube. The solar composite bed comprises: a lower header, an upper header, and the solar composite tube disposed between and communicating with the lower header and the upper header. The lower header and the upper header each comprise an outer casing and inner sleeve. A water header is disposed between the outer casing and the inner sleeve. The inner sleeve is an adsorbate header. The water header of the lower header communicates with the water header of the upper header via water paths of the solar composite tube. The adsorbate header of the lower header communicate with the adsorbate header of the upper header via the inner metal tube of the solar composite tube. A number of the solar composite tube is 15-20.

In another aspect, the invention also provides a solar cold and heat supply system comprising the solar composite bed. The system comprises: at least one or a plurality of the solar composite beds which are connected in parallel with one another, an adsorbate cycling sub-system, a water cycling sub-system, pipes for connecting different sub-systems and devices, and water pumps and valves disposed on the pipes. The adsorbate cycling sub-system comprises: a condenser, a liquid storing tank, and an evaporator. A working medium inlet of the condenser is connected to an adsorbate header of the upper header of the solar composite bed. A working medium outlet of the evaporator is connected to an adsorbate header of the lower header of the solar composite bed. The water cycling sub-system comprises: a hot-water storage tank, a cold-water tank, and a cold-water storage tank; a water outlet of the hot-water storage tank, a water outlet of the cold-water tank, and the water header of the lower header of the solar composite bed communicate with one another. A water inlet of the hot-water storage tank, a water inlet of the cold-water tank, and the water header of the upper header of the solar composite bed communicate with one another. The cold-water storage tank, the cold-water tank, and the evaporator 6 communicate with one another via water cycling pipelines. The hot-water storage tank and the cold-water storage tank are connected to a user.

Compared with the prior art, advantages of the solar composite tube, the solar composite bed, and the solar cold and heat supply system according to embodiments of the invention are summarized as follows:

Compared with conventional solar heat collection tubes, the solar composite tube of the invention has the cooling function when the vacuum pipe collects heat, that is, the solar energy is able to transfer the heat to the absorbent in the composite tube via the vacuum pipe, realizing the heat storage in the daytime. The absorbent is heated to a certain temperature and then exchanges heat with the adsorbate to desorb the adsorbate. The desorbed adsorbate is cooled and stored in the evaporator. In the night, the absorbent is cooled by the water from the water cooling system, the adsorbent after being cooled exchanges heat with the adsorbate to facilitate the adsorption of the adsorbate. And the refrigeration capacity is produced in the evaporation and cooling processes of the adsorbate in the evaporator. The heat collection, adsorption and heat storage, recover, and cooling functions of the solar composite bed are realized by the adsorbate cycling sub-system and the water cycling sub-system. Thus, the utilization efficiency of the solar energy is improved.

The system of the invention is integrated with a cooling pipeline system and a heating pipeline system, in which, the cold water cycling part is innovative and tackle the problem of heat dissipation in adsorption cooling and at the same time recover the adsorbed heat quantity. If the continuous cold and heat supply are required for the whole day, two sets of systems of the same scale are necessitated, at the time one set of system is in the adsorption state, the other set of the system is in the desorption state. During the daytime when the solar irradiation is strong, the adsorption process must utilize a sun-shedding curtain to shed the solar irradiation. The adsorption bed is required to be irradiated according to a certain angle, the sun-shedding curtain is covered on the adsorption bed and mounted on the guiding rails on two sides of the adsorption bed. The up and down sliding of the sun-shedding curtain is driven by rotation of a motor, thus, the covered and naked working conditions are achieved to realize the adsorption and desorption processes. The integrated system of the invention possesses the heating and cooling pipeline systems, in which, the water cooling cycling part is innovative and tackles the difficulty in heat dissipation in adsorption for cooling and recovered the adsorbed heat quantity.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a structure diagram of a solar composite bed in accordance with one embodiment of the invention;

FIG. 2 is a cross sectional view of a solar composite tube of FIG. 1; and

FIG. 3 illustrates a solar cold and heat supply system comprising the solar composite bed in accordance with one embodiment of the invention.

In the drawings, the following numbers are used: 1. Solar composite bed 1.1. Lower header; 1.2. Solar composite tube; 1.3. Upper header; 1.2.1. Solar vacuum tube; 1.2.2. Outer metal tube; 1.2.3. Inner metal tube; 1.2.4. Adsorbent; 2.1-2.6. Water pump; 3. Hot-water storage tank; 4. Condenser; 5. Liquid storing tank; 6. Evaporator; 7. User; 8. Cold-water tank; 9. Cold-water storage tank; 10.1-10.10. Valves; and 11.1-11.2. Vacuum valves.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Specific embodiments of the invention are further described in details combining with the drawings hereinbelow.

As shown in FIG. 2, a solar composite tube 1.2 comprises a solar vacuum tube 1.2.1 having two open ends functioning in thermal collection and insulation. An outer metal tube 1.2.2 and an inner metal tube 1.2.3 are coaxially disposed inside the solar vacuum tube 1.2.1, and both the outer metal tube 1.2.2 and the inner metal tube 1.2.3 are preferably made of metal materials of good thermal conductivity. A water path is formed between the outer metal tube 1.2.2 and the solar vacuum tube 1.2.1. In use, the water is heated and directly supplied to the user. A solid adsorbent 1.2.4 is disposed between the outer metal tube 1.2.2 and the inner metal tube 1.2.3 for exchanging heat with water outside the outer metal tube 1.2.2, therefore realizing desorption of the adsorbent 1.2.4. The inner metal tube 1.2.3 is optionally selected from copper pipes, a plurality of through holes having diameters of 1-2 mm are disposed thereon. The inner metal tube 1.2.3 is used to introduce an adsorbate. A working pair is comprising the adsorbate and the above adsorbent 1.2.4 for realizing the adsorption and desorption of the adsorbate thus accomplishing the heat release and heat adsorption processes. The design of the through holes having the diameter of 1-2 mm is primarily based on the consideration of the adsorption rate and desorption rate of the working pair. It was found from experiments that the through holes having the diameter of 1-2 mm facilitate the adsorption of the adsorbate for the adsorbent 1.2.4, in the meanwhile, the desorption rate can be effectively controlled during the desorption, thus ensuring the continuous release of the desorbed heat.

The working pair comprising the adsorbate and the adsorbent 1.2.4 comprises a gaseous adsorbate and the solid adsorbent, which is advantageous in that the pyrolysis temperature is not highly required and is adaptable to the solar energy, the adsorption and pyrolysis amount and the COP value are relatively high. No additional power device is required. A preferable scheme is methanol-active carbon or ammonia-active carbon, in which, the active carbon is optionally added with a metal powder having good thermal conductivity, such as aluminum powder, then mixed with an organic adhesive, and thereafter adhered to an outer wall of the inner metal pipe 1.2.3, and a weight of the metal powder does not exceed 30 wt. %.

As shown in FIG. 1, the solar composite bed 1 comprising the solar composite tubes. The solar composite bed 1 comprises: a lower header 1.1, an upper header 1.3, and a plurality of the solar composite tubes 1.2 communicating with the lower header 1.1 and the upper header 1.3. Each of the lower header 1.1 and the upper header 1.3 is formed by an outer casing and inner sleeve. A water header is disposed between the outer casing and the inner sleeve. The inner sleeve is an adsorbate header. The water header of the lower header 1.1 communicates with the water header of the upper header 1.3 via water paths of the solar composite tubes 1.2. The adsorbate header of the lower header 1.1 communicate with the adsorbate header of the upper header 1.3 via inner metal tubes 1.2.3 of the collection adsorption composite tubes 1.2.

As shown in FIG. 3, a solar cold and heat supply system comprising the solar composite bed comprises: three solar composite beds 1 arranged in parallel, an adsorbate cycling sub-system, a water cycling sub-system, pipes for connecting different sub-systems and devices, and water pumps 2.1-2.6, valves 10.1-10.10, and vacuum valves 11.1-11.2 disposed on the pipes. The adsorbate cycling sub-system comprises: a condenser 4, a liquid storing tank 5, and an evaporator 6. A working medium inlet of the condenser 4 is connected to an adsorbate header of the upper header 1.3 of the solar composite bed. A working medium outlet of the evaporator 6 is connected to an adsorbate header of the lower header 1.1 of the solar composite bed. The water cycling sub-system comprises: a hot-water storage tank 3, a cold-water tank 8, and a cold-water storage tank 9. A water outlet of the hot-water storage tank 3, a water outlet of the cold-water tank 8, and the water header of the lower header 1.1 of the solar composite bed 1 communicate with one another. A water inlet of the hot-water storage tank 3, a water inlet of the cold-water tank 8, and the water header of the upper header 1.3 of the solar composite bed 1 communicate with one another. The cold-water storage tank 9, the cold-water tank 8, and the evaporator 6 communicate with one another via water cycling pipelines for realizing heat exchange. The hot-water storage tank 3 and the cold-water storage tank 9 are respectively connected to a user 7 for realizing controllable heating or cooling of the user 7.

Working principle of the solar cold and heat supply system is as follows:

1) Heating process: in the daytime when the solar irradiation is strong, the solar energy is adsorbed by the solar composite bed 1, and the water in the solar vacuum pipe 1.2.1 is heated. When the water temperature reaches to a set temperature, start the water pump 2.1, open the valves 10.2, 10.3 and close the valve 10.1 to allow the water in the hot-water storage tank 3 to enter the solar composite bed 1 via the lower header 1.1, after being heated, the water is discharged from the upper header 1.3 and returned to the hot-water storage tank 3 for storage.

2) Cooling process: in the daytime when the solar irradiation is strong, during the heating process, the heated water transfers heat to the adsorbent 1.2.4 which is in the form of a complex by adsorbing methanol. Open the vacuum valve 11.1, generally when the temperature of the adsorbent 1.2.4 reaches 60-70° C., the methanol as the adsorbate begins to desorb. When the temperature reaches 85° C., a large amount of the methanol as the adsorbate is desorbed, ammonia enters the inner metal pipe 1.2.3 via the through hole and then passes through the upper header 1.3 to enter the condenser 4 for cooling. The liquid methanol enters the liquid storage tank 5 and finally enters the evaporator 6 for storage until the desorption of the adsorbent 1.2.4 is finished.

After the sunset or in the daytime when the solar irradiation is shed by a sun-shedding curtain, in the water cycling sub-system: the water temperature in the solar composite bed 1 is decreased, the valves 10.2, 10.4 is closed, the valves 10.1, 10.3 are opened, and the water pump 2.2 is started to extract cold water at 20° C. below from the cold-water tank 8 to the solar composite bed 1 via the lower header 1.1. The cold water exchanges heat with the adsorbent 1.2.4, the temperature of the adsorbent 1.2.4 decreases and is in an adsorbing state. Heat quantity released in the adsorbing process is transferred to the water and therefore the water temperature gradually increases. The heated water is discharged from the upper header 1.3 and introduced to the hot-water storage tank 3, thus, the adsorbed heat quantity is recovered via the hot-water storage tank 3. In the meanwhile, in the adsorbate cycling sub-system, when the temperature of the adsorbent 1.2.4 decreases to 40-50° C., the vacuum valve 11.2 is opened, so that the adsorbent 1.2.4 starts to adsorb methanol. When the temperature of the adsorbent 1.2.4 decreases to 30° C., a large amount of the methanol as the adsorbate is adsorbed, in the meanwhile, the methanol the refrigerant in the evaporator 6 is evaporated for refrigeration. The refrigeration capacity of the refrigerant is transferred to chilled water, and the chilled water is stored in the cold-water storage tank 9 for supply refrigeration capacity for the user 7 for a long period. In the meanwhile, the evaporator 6 or the cold-water storage tank 9 is adopted to replenish the refrigeration capacity of the cold-water tank 8, thus ensuring the normal operation of the system.

In sum, the hot-water storage tank 3 functions in storing heated water for the user 7 as well as recovering adsorbed heat quantity; and the cold-water storage tank 9 functions in storing cold water for the user 7 and replenishing refrigeration capacity for the cold-water tank 8. The cold-water tank 8 functions in facilitating the adsorption of the adsorbate and the heat release process.

The key technology of the invention is the structure arrangement of the solar vacuum pipe 1.2.1, the outer metal tube 1.2.2, the inner metal tube 1.2.3, and the adsorbent 1.2.4 in the solar composite bed. The solar composite tube has the functions of heat collection, adsorption, and desorption. The adsorbate cycling sub-system and the water cycling sub-system are employed to realize the heat collection, heat adsorption, storage, and recover, and refrigeration of the solar composite bed. The use effect of the solar energy is saved, the occupied area and the investment are saved, and the energy efficiency is improved. Thus, the protection of the invention is not limited to the above embodiments. It is obviously to the persons skilled in the art that changes and modifications may be made without departing from the true spirit and scope of the invention. For example, selection of the working pair is not limited to the active carbon-methanol as described in the above, working pairs, including the ammonia-active carbon, which has the not highly required pyrolysis temperature and relatively high adsorption pyrolysis amount and COP value and is adaptable to the solar agent also work. Correspondingly, the pipelines and devices of the adsorbate cycling sub-system can be appropriately adjusted. The specification and the number of the solar composite tubes 1.2 in the solar composite bed 1, and the specification and the number of the solar composite bed 1 in the heating-cooling system are determined according to practical needs. If the changes and the modifications fall within the scope of the claim and the equivalent technique of the invention, then the invention is intended to include such changes and modifications. 

The invention claimed is:
 1. A solar composite tube, comprising: a solar vacuum tube having two open ends, the solar vacuum tube comprising an outer metal tube and an inner metal tube which are coaxially disposed inside the solar vacuum tube; a water path; an adsorbent; and an adsorbate; wherein the water path is formed between the outer metal tube and the solar vacuum tube; the adsorbent is disposed between the outer metal tube and the inner metal tube and is configured to exchange heat with water in the water path outside the outer metal tube; the inner metal tube comprises a plurality of through holes; the adsorbate is disposed in the inner metal tube; and the adsorbate and the adsorbent form an adsorption-desorption working pair.
 2. The tube of claim 1, wherein the through holes on the inner metal tube have diameters of between 1 and 2 mm.
 3. The tube of claim 1, wherein the adsorption-desorption working pair comprises a gaseous adsorbate and a solid adsorbent.
 4. The tube of claim 2, wherein the adsorption-desorption working pair comprises a gaseous adsorbate and a solid adsorbent.
 5. The tube of claim 3, wherein the adsorption-desorption working pair is methanol-active carbon or ammonia-active carbon.
 6. The tube of claim 4, wherein the adsorption-desorption working pair is methanol-active carbon or ammonia-active carbon.
 7. A solar composite bed, comprising: a lower header; an upper header; and the solar composite tube of claim 1, the solar composite tube being disposed between and communicating with the lower header and the upper header; wherein the lower header and the upper header each comprise an outer casing and inner sleeve; a water header is disposed between the outer casing and the inner sleeve; the inner sleeve is an adsorbate header; the water header of the lower header communicates with the water header of the upper header via the water path of the solar composite tube; the adsorbate header of the lower header communicate with the adsorbate header of the upper header via the inner metal tube of the solar composite tube.
 8. The bed of claim 7, wherein the solar composite tube is from 15 to 20 in number.
 9. A solar cold and heat supply system, comprising: at least one or a plurality of the solar composite beds of claim 7 which are connected in parallel with one another; an adsorbate cycling sub-system; a water cycling sub-system; pipes for connecting different sub-systems or devices; and water pumps and valves disposed on the pipes; wherein the adsorbate cycling sub-system comprises: a condenser, a liquid storing tank, and an evaporator; a working medium inlet of the condenser is connected to the adsorbate header of the upper header of the solar composite bed; a working medium outlet of the evaporator is connected to the adsorbate header of the lower header of the solar composite bed; the water cycling sub-system comprises: a hot-water storage tank, a cold-water tank, and a cold-water storage tank; a water outlet of the hot-water storage tank and a water outlet of the cold-water tank communicate with the water header of the lower header of the solar composite bed; a water inlet of the hot-water storage tank and a water inlet of the cold-water tank communicate with the water header of the upper header of the solar composite bed; the cold-water storage tank, the cold-water tank, and the evaporator communicate with one another via water cycling pipelines; and the hot-water storage tank and the cold-water storage tank are connected to a user. 